2000 PreRunner Slooowww Acceleration from a Stop

[c_jernigan]

I have a 2000 Tacoma PreRunner 3.4L V6 TRD Automatic - with just over 170K miles.

At exactly 170,000.0 miles the check engine light came on and I assumed that there was some pre-programed service check that needed to be performed. When I came to the next stop light about 2 miles later it seemed a bit sluggish when accelerating from a complete stop, with only 50 - 60% of the usual acceleration from zero to 15 or 20 MPH - then beyond that it is fine. Basically, the engine revs relatively loud, but it just doesn't go anywhere very fast. You might get a big rush of adrenaline if you pulled out in front of a fast moving dump truck from a complete stop.

I took it in to the Toyota dealership where we have had all warranty maintenance done. They saw one code indicating a possible transmission issue - which they did not disclose - but said drive it for a while and see how it runs. Well, it did fine for about 2 miles and started with the sluggishness again. I took it back and then they suggested 1) shift solenoid 2) new transmission. Since it has 170k and is almost 8 years old I went ahead with the new shift solenoid - which didn't fix the problem. I don't want to put much more $$$ into Toyota's hands because it seems like they are simply guessing. They checked the fluid and there was no metal.

There isn't any shaking, shuddering, thunking or clunking ... it makes all of the same sounds that always has - once it gets up to speed it runs fine. It seems like there is maybe a stuck valve or ... maybe a screwed up sensor??? ... and it was just really odd when the check engine light came on at 170,000 - I have ADD so I notice orange lights, odd sounds, etc in an instant. The sluggishness seems like the first 2 or 3 minutes on a really cold morning. Interestingly, the acceleration is somewhat better on cooler mornings. Today the temps are only in the 50s and it seems moderately better.

Suggestions, insights?

[Flash75]

I assume the fluid was changed when the shift solenoid was changed, if not I would have the fluid changed jut to rule it out as the problem. It sounds like you may have low pressure or some worn clutches in the transmission. The shop manual specifies some checks to help determine where a problem is. The checks they should run are, stall speed, pressure testing and shift delay times. These checks are in the manual, you can download the manual for your truck here.
http://www.ncttora.com/fsm/index.html
I think the check engine coming on at the specific mileage may be a coincidence and not related to some maintenance reminder. I would try a good transmission shop unless you are sure your Toyota dealer has a good transmission specialist. Either way the transmission may need to be removed to correct the problem.

Clifton

[c_jernigan]

Thanks Clifton

I think that this particular dealership is no longer very good. It seemed great for a 3 - 4 years then they switched shop or team managers and it has been downhill ever since. I noticed that all of their service awards were all dated 2004 or later. Hmmm ... ;-)

I'm planning to take it to non-dealership shop later today.
I did find out that in all of our scheduled maintenance, that the timing belt had never been changed - does anyone think that this could potentially be the root cause of the problem?

[TcmaBoy]

If your timing belt is worn out you could experience hesitation and misfires. If it has not been replaced within the last 70000 miles or so, then it is time. Do the water pump while you are in there.